淇河鲫(Carassius auratus in Qihe river)是河南省特有的名贵优质鱼类,其体型丰满、体色鲜亮、营养丰富.淇河鲫的繁殖方式为天然雌核发育,故多为三倍体.本研究选取14条健康的成熟淇河鲫雌鱼,取卵子混合后,分别用淇河鲫、荷包红鲤、红...淇河鲫(Carassius auratus in Qihe river)是河南省特有的名贵优质鱼类,其体型丰满、体色鲜亮、营养丰富.淇河鲫的繁殖方式为天然雌核发育,故多为三倍体.本研究选取14条健康的成熟淇河鲫雌鱼,取卵子混合后,分别用淇河鲫、荷包红鲤、红鲫、黄河鲤的成熟精子刺激并采用干法授精的方式进行人工授精.孵化后培育,分别在5月龄及7月龄时测量4种精子刺激的淇河鲫子代的体长、体高、体宽和体质量,运用SPSS 22.0软件对不同性状的平均值、标准差、显著性检验.结果表明,与异源精子刺激产生的淇河鲫子代相比,同源精子刺激产生的后代生长性状较差.而黄河鲤精子刺激产生的子代生长性状最好.该实验支持并验证了“异精生物学效应”假说,为淇河鲫的种质资源保护和雌核发育研究提供参考,具有一定的社会和经济价值.展开更多
Time reversal processing （TRP） might be regarded as matched field processing with known environmental knowledge. However, the performance of TRP is degraded in an uncertain environment. A technique based on the Maxi...Time reversal processing （TRP） might be regarded as matched field processing with known environmental knowledge. However, the performance of TRP is degraded in an uncertain environment. A technique based on the Maximin criterion is pro- posed for enhancing the robustness of TRP in a waveguide with uncertain water depth. The relationship between the water depth and the focal spot translation is examined based on the waveguide-invariant theory. Then the time reversal transmissiou scheme with the Maximin criterion is performed to maximize the minimum transmission power on a target of interest. At the receiving end, coherent summation operation is carried out over the received data by a reception focusing bank. If it is neces- sary to enhance the target echo further, the iterative time reversal can be considered where the target echo corresponding to the first time reversal transmission is regarded as a secondary source. Numerical simulations and experimental results of the target localization in a waveguide tank have verified the effectiveness of robust TRP.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.60872066 and 61171148)the National High-Tech R&D Program of China(Grant No.2009AA093601-3)
文摘Time reversal processing （TRP） might be regarded as matched field processing with known environmental knowledge. However, the performance of TRP is degraded in an uncertain environment. A technique based on the Maximin criterion is pro- posed for enhancing the robustness of TRP in a waveguide with uncertain water depth. The relationship between the water depth and the focal spot translation is examined based on the waveguide-invariant theory. Then the time reversal transmissiou scheme with the Maximin criterion is performed to maximize the minimum transmission power on a target of interest. At the receiving end, coherent summation operation is carried out over the received data by a reception focusing bank. If it is neces- sary to enhance the target echo further, the iterative time reversal can be considered where the target echo corresponding to the first time reversal transmission is regarded as a secondary source. Numerical simulations and experimental results of the target localization in a waveguide tank have verified the effectiveness of robust TRP.
